JP2003137504A - Fuel reformer and its warming-up method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology to reduce the warming-up time of a fuel cell system. SOLUTION: The reformer 36 is provided with the first reaction part 21 and the second reaction part 22. In steady operation, gas fed to the reformer 36 undergoes reforming reaction by passing through the first reaction part 21 and the second reaction part 22, and then being fed to a shift part 38. When warming-up, the gas passes through the first reaction part 21 and is fed to the shift part 38 through a bypass channel 77 without passing through the second reaction part 22 until the warming-up state of the shift part 38 reaches the predetermined condition. Thereby, high-temperature gas can be fed to the shift part 38 regardless of the warming-up condition of the second reaction part 22 when the temperature of the first reaction part 21 goes up to a certain degree.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel reformer for reforming a hydrocarbon fuel to produce a hydrogen-rich gas and a method for warming up the fuel reformer.

[0002]

2. Description of the Related Art As a method of supplying a fuel gas to a fuel cell, there is known a method of reforming a raw fuel such as hydrocarbon to produce a hydrogen rich gas and using the hydrogen rich gas as the fuel gas. In such a case, in a fuel reformer that reforms a hydrocarbon-based fuel to generate a hydrogen-rich gas, the raw fuel or water used for the reforming reaction is vaporized / heated and supplied from the vaporizer. A plurality of reactors, such as a reformer that advances the reforming reaction using the generated raw fuel and steam, and a carbon monoxide reduction unit that reduces the carbon monoxide concentration in the hydrogen-rich gas produced in the reformer Set up. The reaction that proceeds in these plural reactors is a chemical reaction, and each of the above-mentioned reactors is equipped with a catalyst that promotes such a chemical reaction inside.

At the time of starting such a fuel reformer, it is necessary to raise the temperature of each reactor until the temperature of the catalyst provided in each reactor becomes sufficient. When warming up at the time of starting the fuel reformer, normally, the high-temperature gas heated in the evaporation section is sequentially supplied to the reactor on the downstream side, and the heat of the high-temperature gas causes the upstream temperature to rise. The temperature is sequentially raised from the reactor arranged on the side.

[0004]

As described above, when the temperature of each reactor is increased by the high temperature gas supplied from the upstream side, after the temperature of the reactor arranged on the upstream side is sufficiently increased. Otherwise, the reactor arranged on the downstream side will not be sufficiently heated. That is, while the temperature of the upstream reactor is low, the heat of the high temperature gas is used to raise the temperature of the upstream reactor, so only the cooled gas is supplied to the downstream reactor. . Therefore, at the time of starting the fuel reformer, the temperature of the plurality of reactors must be sequentially raised from the upstream side to raise the temperature of all the reactors sufficiently, so that the hydrogen concentration is sufficiently high and the carbon monoxide concentration is low. Cannot be supplied to the fuel cell.

In the fuel cell system equipped with the fuel reformer, the temperature of each of the reactors is sufficiently raised and the warming up is completed at the time of startup, so that steady operation (power generation for obtaining desired power is performed. Can be done). Therefore, in the fuel cell system, it has been desired to shorten the warm-up time of the fuel reformer.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a technique for further shortening the warm-up time in the fuel reformer.

[0007]

In order to achieve the above object, the first fuel reformer of the present invention is a fuel reformer for reforming a hydrocarbon fuel to produce a hydrogen rich gas. And a first gas inflow port, a first gas outflow port, the first gas inflow port and the first gas, and a catalyst for accelerating the reaction related to the production of the hydrogen-rich gas. A gas that has passed through the first reaction part and a first reaction part having a bypass gas outlet provided between the first reaction part and a catalyst for accelerating a reaction relating to the production of the hydrogen-rich gas. A second reaction part having a second gas inflow port to which is supplied and a second gas outflow port, the bypass gas outflow port, and a bypass flow path connecting the second gas inflow port And determine the warm-up state in the second reaction section At least a part of the gas introduced into the first reaction section until the warm-up state determination unit determines that the warm-up state has reached a predetermined state by the warm-up state determination unit. And a flow path switching unit that switches a gas flow path so that the gas is supplied to the second reaction unit via the bypass flow path.

When the fuel reformer is started, the temperature of the catalyst gradually rises from the upstream side of the first reaction section. At this time, in the first reaction section, at least a part of the gas introduced into the first reaction section is bypassed until it is determined that the warm-up state of the second reaction section has reached a predetermined state. Since it is supplied to the second reaction part, compared with the case where the entire amount of the gas introduced into the first reaction part is supplied to the second reaction part via the first gas outlet, A high temperature gas can be supplied to the second reaction section. That is, the high-temperature gas that has passed through the upstream portion of the first reaction portion is passed through to the downstream portion of the first reaction portion where the warm-up is insufficient, so that the temperature is not lowered by the second
Can be supplied to the reaction section of By this, the second
It becomes possible to raise the temperature of the reaction part of the above-mentioned more quickly, and the warm-up time can be shortened.

In the first fuel reforming apparatus of the present invention, the first reaction section may be a reforming section including a reforming catalyst that promotes a reforming reaction.

In the first fuel reformer of the present invention, the first reaction section is provided with a shift catalyst that promotes a shift reaction for producing hydrogen and carbon dioxide from carbon monoxide and water vapor. It may be part.

A second fuel reformer of the present invention is a fuel reformer for reforming a hydrocarbon fuel to produce a hydrogen-rich gas, which is connected in series so that the gas sequentially passes from the upstream side. A plurality of reaction parts, each of which has a reaction chamber for accommodating a catalyst that promotes an exothermic reaction related to the production of the hydrogen-rich gas, and a gas supplied to the reactor. A bypass flow path for guiding a part of the above to a downstream reaction section other than the most upstream reaction section without passing through the most upstream reaction section of the plurality of reaction sections. A warm-up state determination unit that determines a warm-up state in the downstream reaction unit, and the reaction until the warm-up state determination unit determines that the warm-up state has reached a predetermined state. Part of the gas supplied to the vessel is the bypass flow. As it supplied to the reaction portion of the downstream side via, and summarized in that and a passage switching unit for switching the flow path of the gas.

When the fuel reformer is started, the temperature gradually rises from the reaction section on the upstream side, and the reaction related to the production of hydrogen-rich gas is started in the reaction section arranged at the most upstream side. At this time, until it is determined that the warm-up state in the reaction section on the downstream side other than the reaction section arranged at the most upstream reaches a predetermined state, a part of the gas supplied to the reactor is
Since it is guided to the downstream reaction section without passing through the most upstream reaction section, an exothermic reaction occurs in the downstream reaction section regardless of the warm-up state of the most upstream reaction section. Can start. As a result, the temperature of the reaction section on the downstream side can be raised more quickly, and the warm-up time can be shortened.

In the second fuel reforming apparatus of the present invention, the reactor may be a reforming section equipped with a reforming catalyst that promotes a reforming reaction.

Further, in the second fuel reforming apparatus of the present invention, the reactor is equipped with a catalyst for promoting a carbon monoxide selective oxidation reaction in which hydrogen monoxide preferentially oxidizes carbon monoxide in hydrogen-rich gas. It may be a carbon oxide selective oxidation part.

The present invention can be implemented in various modes, for example, a method for warming up a fuel reformer,
The present invention can be implemented in various forms such as a fuel cell system including a fuel reforming device, a method for warming up the fuel cell system, and a moving body equipped with the fuel cell system.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in the following order based on examples. A. Overall configuration of device: B. Configuration related to warming up promotion: C. Operation at startup: D. Modification of First Embodiment: E. Second Example: F. Modification of Second Embodiment: G. Other variants:

A. Overall Configuration of Device: FIG. 1 is a block diagram showing a schematic configuration of a fuel cell system 10 as a first embodiment of the present invention. First, the fuel cell system 10
The overall configuration of and the gas flow during steady operation will be described. The fuel cell system 10 includes a reformed fuel tank 30 that stores reformed fuel and a water tank 3 that stores water.
2, an evaporator 34 including a heating unit 50, a reformer 36 that generates a hydrogen-rich gas by a reforming reaction, a shift unit 38 that reduces the carbon monoxide (CO) concentration in the hydrogen-rich gas by a shift reaction, and a A CO selective oxidizer 39 for reducing the concentration of carbon monoxide by an oxidation reaction, a fuel cell 40 for obtaining an electromotive force by an electrochemical reaction, a blower 42 for compressing air to supply the fuel cell 40, and a controller 60 composed of a computer. Is the main component. In this example, gasoline was used as the reforming fuel.

A part of the gasoline stored in the reformed fuel tank 30 is supplied to the evaporator 34 as a reformed fuel via the fuel passage 70. In addition, a part of the gasoline stored in the reformed fuel tank 30 is used as a combustion fuel for the heating unit 5 via a branch passage 71 that branches from the fuel passage 70.
Supplied to zero. The fuel flow passage 70 is provided with a pump 57, and the branch passage 71 is provided with a pump 56. The pumps 56 and 57 are connected to the control unit 60 and are driven by a signal output from the control unit 60,
The amount of gasoline supplied to the heating unit 50 and the evaporator 34 is controlled.

The water stored in the water tank 32 is supplied to the evaporator 34 via the water flow path 72. The water flow path 72 and the fuel flow path 70 merge to form a fuel flow path 73, which is connected to the evaporator 34. Water passing through the water flow passage 72 and gasoline passing through the fuel flow passage 70 are mixed in the fuel flow passage 73 and supplied to the evaporator 34. A pump 58 is provided in the water flow path 72. The pump 58 is connected to the control unit 60, is driven by a signal output from the control unit 60, and adjusts the amount of water supplied to the evaporator 34 via the water flow path 72.

The evaporator 34 is a device for vaporizing the gasoline supplied from the reformed fuel tank 30 and the water supplied from the water tank 32. The evaporator 34 receives the supply of gasoline and water from the steam and gasoline gas. Is formed into a mixed gas, which is heated to a predetermined temperature and discharged. The mixed gas discharged from the evaporator 34 is supplied to the reformer 36 via the fuel gas passage 74.

The evaporator 34 is provided with a heating section 50 as a heat source for vaporizing water and gasoline.
The heating unit 50 receives gasoline supplied from the reformed fuel tank 30 and anode exhaust gas discharged from a fuel cell described later. The heating unit 50 also receives the supply of compressed air from the blower 52. The heating unit 50 is provided with a combustion catalyst therein, performs a combustion reaction using the gasoline, the anode exhaust gas, and the air, and supplies the generated fuel gas to the evaporator 34. The gasoline and water supplied to the evaporator 34 are heated in the evaporator 34 by exchanging heat with the combustion gas while passing through the evaporator 34. Heating part 5
At 0, the amount of heat generated is controlled by controlling the amounts of the gasoline and anode exhaust gas supplied to the heating unit 50, whereby the evaporator 34 changes the mixed gas according to the temperature of the reforming reaction. The temperature is raised to the desired temperature.

The reformer 36 has a reforming catalyst inside and reforms the supplied mixed gas to produce hydrogen-rich fuel gas. As the reforming catalyst, noble metals such as platinum, palladium and rhodium, or alloys thereof can be used. In addition, in the reformer 36 of the present embodiment, when the hydrogen-rich gas is generated, in addition to the steam reforming reaction, the partial oxidation reaction accompanied by the generation of hydrogen simultaneously proceeds. Since the partial oxidation reaction is an exothermic reaction, when the steam reforming reaction proceeds, the heat generated by the partial oxidation reaction is used in addition to the heat carried by the mixed gas from the evaporator 34. A blower 53 for supplying air from the outside to the reformer 36 in order to supply oxygen necessary for this partial oxidation reaction.
Is attached. The blower 53 is connected to the control unit 60, and its drive state is controlled by the control unit 60.

As described above, in the fuel cell system 10 of this embodiment, air is supplied to the reformer 36 so that the heat required for the steam reforming reaction is covered by the heat generated by the oxidation reaction. The vessel 36 may generate hydrogen only by the steam reforming reaction without performing the oxidation reaction. Alternatively, the steam reforming reaction, which has a high efficiency of generating hydrogen, may be allowed to proceed more than the partial oxidation reaction. In such a configuration, the reformer 36 may be provided with a heating device such as a heater in order to supply the heat required for the steam reforming reaction.

The hydrogen-rich gas fuel gas produced in the reformer 36 is supplied to the shift section 38 via the gas flow path 75. The shift unit 38 is a device that reduces the concentration of carbon monoxide in the supplied hydrogen-rich gas. The hydrogen-rich gas produced by the reforming reaction from the mixed gas in the reformer 36 contains a predetermined amount (about 10%) of carbon monoxide, but the shift unit 38 has a carbon monoxide concentration in the hydrogen-rich gas. Is reduced.

The shift unit 38 is a device for reducing the concentration of carbon monoxide in the hydrogen-rich gas by advancing a shift reaction which causes carbon monoxide and water to generate hydrogen and carbon dioxide. It is equipped with a catalyst that promotes As a catalyst for promoting such a shift reaction, a low temperature catalyst such as a copper catalyst, a high temperature catalyst such as an iron catalyst, or a noble metal catalyst including platinum can be used. The shift unit 38 may include any shift catalyst, or may be configured to further reduce the carbon monoxide concentration by combining a plurality of types of catalysts described above. The type of shift catalyst included in the shift unit 38 is appropriately selected according to the concentration of carbon monoxide in the hydrogen-rich gas discharged from the reformer, the limit of the concentration of carbon monoxide in the fuel gas required by the fuel cell 40, and the like. Just select it. The shift unit 38 of the present embodiment has a Cu—Zn catalyst. Below, as the formula (1), a formula representing a shift reaction promoted by the shift catalyst is shown.

CO + H ₂ O → CO ₂ + H ₂ +40.5 (kJ / mol) (1)

Although not shown in FIG. 1, a heat exchanger may be provided between the reformer 36 and the shift section 38. The reformer 36 usually has an internal temperature of 6
The reforming reaction of gasoline is controlled under the condition that the temperature is 00 ° C. or higher.
Under the above-mentioned catalyst, it proceeds well in the temperature range of 200 ° C to 400 ° C. Therefore, by providing a heat exchanger between the reformer 36 and the shift unit 38 and sufficiently lowering the temperature of the hydrogen-rich gas discharged from the reformer 36 and then supplying the hydrogen-rich gas to the shift unit 38, it is not desirable. It is possible to prevent the high temperature gas from being supplied to the shift portion 38.

The hydrogen-rich gas, the carbon monoxide concentration of which has been reduced by the shift section 38, is supplied to the CO selective oxidation section 39 via the flow path 76. The CO selective oxidization unit 39 includes a shift unit 3
8 is a device for further reducing the concentration of carbon monoxide in the hydrogen-rich gas supplied from No. 8. That is, in the shift unit 38, the carbon monoxide concentration in the hydrogen-rich gas is reduced to about several percent, while in the CO selective oxidation unit 39, the carbon monoxide concentration is reduced to about several ppm. The reaction that proceeds in the CO selective oxidation unit 39 is a carbon monoxide selective oxidation reaction that oxidizes carbon monoxide in preference to hydrogen that is abundant in the hydrogen-rich gas. The CO selective oxidation unit 39 is provided with a carrier carrying a platinum catalyst, a ruthenium catalyst, a palladium catalyst, a gold catalyst, which is a selective oxidation catalyst for carbon monoxide, or an alloy catalyst having these as the first element. Under such a carbon monoxide selective oxidation catalyst, the carbon monoxide selective oxidation reaction proceeds well by maintaining the reaction temperature at 100 ° C to 200 ° C.

In order to supply oxygen required for the carbon monoxide selective oxidation reaction which proceeds in the CO selective oxidation section 39, C
A blower 54 is attached to the O selective oxidation unit 39.
The blower 54 takes in air from the outside, compresses it, and supplies it to the CO selective oxidizing section 39. The blower 54 is connected to the control unit 60, and the amount of air (oxygen) supplied to the CO selective oxidation unit 39 is adjusted by the control unit 60.

The hydrogen-rich gas whose carbon monoxide concentration has been lowered by the CO selective oxidation unit 39 as described above is guided to the fuel cell 40 by the fuel gas flow passage 78 and is used as fuel gas for the cell reaction on the anode side. . The anode exhaust gas after being subjected to the cell reaction in the fuel cell 40 is discharged to the anode exhaust gas passage 79 and guided to the heating unit 50, and the hydrogen remaining in the anode exhaust gas is consumed as fuel for combustion. . On the other hand, the oxidizing gas involved in the cell reaction on the cathode side of the fuel cell 40 is supplied by the blower 42, which outputs a drive signal from the control unit 60, to the oxidizing gas flow path 43
Is supplied as compressed air via. The remaining cathode exhaust gas used in the cell reaction is discharged to the outside.

The fuel cell 40 is a solid polymer electrolyte type fuel cell, and is constituted by stacking a plurality of unit cells each having an electrolyte membrane, an anode, a cathode, and a separator. The electrolyte membrane is a proton conductive ion exchange membrane formed of a solid polymer material such as a fluorine resin. Both the anode and the cathode are formed of carbon cloth woven of carbon fibers. Further, a catalyst layer including a catalyst that promotes an electrochemical reaction is provided between the electrolyte membrane and the anode or the cathode.
As such a catalyst, platinum or an alloy of platinum and another metal is used. The separator is formed of a gas-impermeable conductive member such as dense carbon that is gas-impermeable by compressing carbon or a metal having excellent corrosion resistance. Further, this separator forms a flow path for the fuel gas and the oxidizing gas between the anode and the cathode. The fuel cell 40 is supplied with hydrogen-rich gas as a fuel gas and compressed air as an oxidizing gas in the flow path to generate an electromotive force by advancing an electrochemical reaction. The electric power generated by the fuel cell 40 is supplied to a predetermined load connected to the fuel cell 40. less than,
4 shows an electrochemical reaction that proceeds in the fuel cell 40. The equation (2) shows the reaction on the anode side, the equation (3) shows the reaction on the cathode side, and the reaction shown by the equation (4) proceeds in the entire battery.

H ₂ → 2H ⁺ + 2e ⁻ (2) (1/2) O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (3) H ₂ + (1/2) O ₂ → H ₂ O (4) )

The control unit 60 is constructed as a logic circuit centering on a microcomputer, and more specifically, a CPU 64 for executing a predetermined calculation according to a preset control program and a CPU 64 for executing various calculation processes. A ROM 66 in which necessary control programs, control data, etc. are stored in advance, and various data required for various arithmetic processing in the CPU 64 are also temporarily read and written.
The AM 68 and the detection signals from the various sensors included in the fuel cell system 10 and the information relating to the load connected to the fuel cell are input, and the blowers and pumps described above are input to each of the blowers and pumps according to the calculation result of the CPU 64. An input / output port 62 for outputting a drive signal and the like are provided. The control unit 60 controls the operating state of the entire fuel cell system 10 by inputting and outputting various signals in this manner.

B. Configuration related to warm-up promotion: FIG. 2 shows a reformer 36 and a shift unit 38 in the fuel cell system 10.
It is an explanatory view showing the state of and the connection in more detail. The reformer 36 includes a first reaction section 21 and a second reaction section 22 inside thereof. Each of the first reaction section 21 and the second reaction section 22 is provided with a honeycomb that carries the above-mentioned reforming catalyst on its surface. From the fuel gas flow path 74 to the reformer 3
The mixed gas supplied to No. 6 is supplied to the reforming reaction while passing through the honeycomb provided in each of the first reaction section 21 and the second reaction section 22 in this order, and the hydrogen-rich gas generated by the reforming reaction is The gas is discharged to the gas flow path 75.

A bypass flow passage 77 is provided as a flow passage connecting the reformer 36 and the shift portion 38.
In the reformer 36, one end of the bypass flow passage 77 has a first
An opening is formed in the space between the reaction section 21 and the second reaction section 22. Further, the other end of the bypass flow passage 77 is connected to the gas flow passage 75. Therefore, the first reaction section 2 of the reformer 36
When the gas that has passed through 1 passes through the bypass passage 77, the shift portion 38 does not pass through the second reaction portion 22.
Is supplied to. A valve 25 is provided in the bypass flow passage 77 and a valve 24 is provided in the gas flow passage 75, and the opening degrees of these valves are controlled by the control unit 60. By controlling the openings of the valves 24 and 25, the amount of gas passing through the second reaction section 22 and the amount of gas passing through the bypass passage 77 are controlled.

Further, the shift section 38 is provided with a temperature sensor 23 for detecting the catalyst temperature of the upstream section thereof. The detection signal of the temperature sensor 23 is input to the control unit 60.

C. Operation at Startup: FIG. 3 is a flowchart showing a reformed gas flow path control processing routine executed by the control unit 60 at startup of the fuel cell system 10. This routine is executed when the fuel cell system 10 is started. When this routine is started, the control unit 60
A drive signal is output to the valves 24 and 25 to close the valve 24 and open the valve 25 (step S100). When the fuel cell system 10 is started, gasoline is supplied to the heating unit 50 to start a combustion reaction in the heating unit 50, and gasoline and water are supplied to the evaporator 34 to be vaporized / heated and mixed. The gas is supplied to the reformer 36. Step S100
By controlling the open / closed state of each valve as described above, the gas that has passed through the first reaction section 21 of the reformer 36 at the time of startup of the fuel cell system 10 passes through the bypass passage 77 and the shift section. 38.

When the high temperature mixed gas is supplied from the evaporator 34, the inside of the reformer 36 is sequentially warmed by the mixed gas from the upstream side of the first reaction section 21. As the catalyst temperature rises, the steam reforming reaction and the partial oxidation reaction gradually proceed in the first reaction section 21. Then, by continuing the heating with the high temperature mixed gas, the temperature of the first reaction section 21 is raised to a temperature at which the activity of the steam reforming reaction and the partial oxidation reaction is sufficiently ensured. It should be noted that when the temperature of the first reaction section 21 rises, the heat of the first reaction section 21 is also transferred to a portion having a lower temperature. Therefore, as the first reaction section 21 is heated, the second reaction section 22 also rises in temperature.

For a while after the warm-up of the fuel cell system 10 is started, the heat of the mixed gas supplied to the reformer 36 is mainly used for heating the first reaction section 21. Therefore, the gas that passes through the first reaction section 21 and is supplied from the bypass flow passage 77 to the shift section 38 has a low temperature at the beginning. However, the first reaction part 21
As the temperature rises as described above, the temperature of the gas supplied to the shift unit 38 also gradually rises, so that the shift unit 38 also rises in temperature.

Next, by inputting the detection signal of the temperature sensor 23, the catalyst temperature T ₁ of the upstream portion of the shift portion 38 is increased.
Is input (step S110). Next, the catalyst temperature T ₁ is compared with a preset reference temperature T _A (step S120). Here, the predetermined reference temperature T _A is such that, in the shift unit 38, when the reformed gas having a sufficiently high temperature is supplied from the reformer 36, the shift reaction can proceed with sufficient activity. The catalyst temperature is a preset temperature. For example, it can be set to a temperature at which the reaction proceeds without any problem under the condition of performing steady operation.

In step S120, the catalyst temperature T ₁
When it is determined that is equal to or lower than the reference temperature T _A , the process returns to step S110 and the catalyst temperature T ₁ is input again. Thus, in step S120 until the catalyst temperature T ₁ is is determined that exceeds the reference temperature T _A, it is repeated and loading of the catalyst temperatures T _1, the operation of the comparison between the reference temperature T _A.

In step S120, the catalyst temperature T ₁
When it is determined that the temperature exceeds the reference temperature T _A , the valves 24, 2
A drive signal to 5 to open the valve 24 and close the valve 25 (step S130),
This routine ends. By driving the valves 24 and 25 as described above, the gas supplied to the reformer 36 does not flow into the bypass flow passage 77 after passing through the first reaction section 21, and the second reaction section 22. Through the shift unit 38
Will be supplied to.

According to the fuel cell system 10 of the present embodiment configured as described above, when warming up at startup,
Until the temperature of the catalyst provided in the shift unit 38 rises to some extent,
The high temperature gas that has passed through the first reaction section 21 of the reformer 36 is
It is supplied to the shift unit 38 without passing through the second reaction unit 22. Therefore, the warm-up time of the entire fuel cell system 10 can be shortened.

Warming up the reactor equipped with the catalyst means an operation of raising the catalyst temperature to a predetermined temperature (range) at which the catalyst activity is sufficiently high. Until such a temperature is reached, the heat applied to the reactor is largely consumed to raise the temperature of the catalyst and the catalyst base material inside the reactor. It is necessary to continue to supply the amount of heat above. The amount of heat consumed for raising the temperature decreases as the catalyst temperature rises. When the catalyst temperature rises above the above-mentioned predetermined temperature, the reaction will actively proceed in that temperature environment, steady operation becomes possible, and gas with sufficient temperature will be discharged from the reactor. become.

In the present embodiment, during warm-up, the gas that has passed through the first reaction section 21 does not pass through the second reaction section 22 and is transferred to the shift section 38 until the temperature of the shift section 38 rises sufficiently. We are supplying. Therefore, when the temperature of the first reaction section 21 rises and the reaction becomes vigorous,
It is possible to supply a high temperature gas to the shift unit 38 and raise the temperature thereof before the temperature of the second reaction unit 22 is sufficiently raised. At that time, the reaction is proceeding while the first reaction section 21 is maintained at a predetermined temperature, and the second reaction section 22 is also heated by heat transfer, so that the shift section 38 is warmed up at the same time. Then, the warming-up of the second reaction section 22 also proceeds. On the other hand, when the gas is supplied in the order of the first reaction section 21, the second reaction section 22, and the shift section 38, the second reaction section 22
Must be sufficiently raised to discharge the high temperature gas from the second reaction section 22, the warm-up of the shift section 38 cannot proceed. Therefore, by using the bypass flow path 77 during warm-up as in the present embodiment, the warm-up time can be shortened as compared with the case where the warm-up is sequentially advanced from the upstream reactor.

In particular, when the fuel cell system 10 is started, the amount of supply gas (the amount of mixed gas supplied from the evaporator 34) is usually suppressed, so that the effect of shortening the warm-up time becomes remarkable. That is, each reactor such as the reformer 36 is
When the required load on the fuel cell 40 becomes maximum,
Although it has a size capable of generating a required amount of fuel gas, during normal warm-up, a smaller amount of gas is supplied than when the load becomes maximum. During warm-up, it is impossible to generate a fuel gas having a sufficiently high hydrogen concentration and a sufficiently low carbon monoxide concentration, and the gas that has passed through each reactor cannot be supplied to the fuel cell 40. This is because the amount of reformed fuel supplied to the evaporator 34 side is suppressed in order to suppress fuel consumption. The smaller the amount of high-temperature gas supplied from the upstream side, the more difficult it is to warm up. However, as in the embodiment, before the second reaction section 22 is sufficiently heated, the high-temperature gas that has passed through the first reaction section 21 By supplying the gas to the shift unit 38, the warm-up time can be effectively shortened. For example, when the fuel cell system 10 is mounted on a vehicle and is used as a power source for driving the vehicle, it is possible to shorten the warm-up time of the vehicle and allow the vehicle to normally travel faster.

FIG. 4A shows how the catalyst temperature of the shift section 38 changes after the warm-up operation is started. The elapsed time t _A when the catalyst temperature reaches the temperature T _A and step S130 shown in FIG. 3 is executed to stop the use of the bypass passage 77 is shown in the figure. It is conceivable that the catalyst temperature of the second reaction section 22 has not risen sufficiently at the elapsed time t _A. In such a case, FIG.
As shown in (A), after the elapsed time t _A , the second reaction part 2
When the gas that has passed through 2 is supplied, the catalyst temperature once drops. Even in such a case, the catalyst temperature of the shift unit 38 may be maintained within a temperature range in which the activity is sufficiently high (the temperature range indicated by the arrow in the figure).

The temperature sensor 23 provided in the shift unit 38 for detecting the warm-up state of the shift unit 38 may be provided anywhere in the shift unit 38.
In this embodiment, as described above, the shift portion 38 is provided near the inlet portion. With this, at least near the inlet of the shift unit 38, when the temperature reaches a temperature at which the shift reaction can proceed with sufficiently high activity when the reformed gas is supplied, this can be detected. Since the shift reaction is an exothermic reaction, once the temperature near the inlet reaches the above-mentioned temperature, the heat generated by the reaction can be utilized to further advance the warm-up.

Further, the temperature sensor 23 does not need to directly detect the temperature of the shift catalyst provided in the shift section 38, and it is sufficient that the temperature sensor 23 can detect the temperature that reflects the temperature of the shift catalyst. For example, the temperature of the gas passing through the shift unit 38 may be detected.

D. Modification of First Embodiment: Furthermore, the following modifications can be made to the above embodiment.

D1. Modified Example 1 of First Embodiment In the fuel cell system 10 of the first embodiment, the inside of the reformer 36 is divided into the first reaction section 21 and the second reaction section 22. However, it may be divided into three or more. FIG. 5 is a reformer 13 as a modification of the first embodiment.
FIG. 6 is an explanatory view showing a state of 6 and bypass flow paths 177 and 178 connected thereto. The reformer 136 is a fuel cell system 1 similar to the fuel cell system 10 shown in FIG.
At 0, it is provided instead of the reformer 36. In the following description, the same parts as those of the fuel cell system 10 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The reformer 136 includes the first reaction section 121 and the second reaction section 121.
The reaction part 122 and the 3rd reaction part 123 are provided. Like the first reaction section 21 and the second reaction section 22 in the reformer 36, the first reaction section 121 to the third reaction section 123 each include a honeycomb that carries a reforming catalyst. The mixed gas supplied from the fuel gas passage 74 to the reformer 136 is the first reaction unit 12
After passing through the first reaction section 122, the second reaction section 122, and the third reaction section 123 in this order, the reforming reaction is performed.

A bypass channel 177 is provided by connecting the space between the first reaction section 121 and the second reaction section 122 to the gas channel 75. Further, a bypass flow path 178 is provided by connecting the space between the second reaction section 122 and the third reaction section 123 and the gas flow path 75. The bypass flow paths 177 and 178 are respectively provided in the control unit 60.
Valves 125 and 126 are provided which are driven by. By opening the valve 125, a part of the gas that has passed through the first reaction section 121 does not pass through the second reaction section 122 and the third reaction section 123, and the shift section 38
Be led to. Further, by opening the valve 126, part of the gas that has passed through the first reaction section 121 and the second reaction section 122 is guided to the shift section 38 without passing through the third reaction section 123.

In such a reformer 136, at the time of warming up, at least a part of the gas supplied to the reformer 136 passes through the bypass flow path 177 or 178, so that at least the valves 125 and 126 are provided. By controlling one of them, the effect of shortening the warm-up time of the reformer 136 can be obtained. That is, if at least a part of the high-temperature gas that has passed through the first reaction section 121 or the second reaction section 122 is guided to the shift section 38 without passing through the third reaction section 123, the shift section 38 can be moved faster. The temperature can be raised, and as a result, the warm-up time of the entire reformer 136 can be shortened. At this time, the third reaction part 123
When the gas is supplied from the upstream side, the temperature is raised by this gas, and is also raised by the heat transfer from the upstream-side reaction part, which has been previously heated. The same effect can be obtained as long as the hot gas that has passed through the upstream portion of the reformer can be supplied to the shift portion 38 without passing through the downstream portion of the reformer during the warm-up operation. .

D2. Modification 2 of First Embodiment: Also, First
In the fuel cell system 10 of the embodiment, the bypass passage is provided between the reformer 36 and the shift unit 38,
A bypass flow path that connects other reactors may be provided. FIG. 6 shows that a similar bypass flow is provided between the evaporator 34 and the reformer 36, and between the shift unit 38 and the CO selective oxidation unit 39, in addition to between the reformer 36 and the shift unit 38. It is a block diagram showing a mode that a path is provided.

As described above, the evaporator 34 is provided with a flow path through which gasoline and water pass, and a flow path for combustion gas supplied from the heating section 50. It is a heat exchanger that performs heat exchange between the two. Shortening the warm-up time of the reformer 36 by providing a bypass flow passage that connects the reformer 36 with a portion in the flow passage in the evaporator 34 through which gasoline and water pass. Is possible. Until the catalyst temperature becomes sufficiently high in at least the upstream portion of the reformer 36, the high temperature mixed gas is reformed through the bypass passage even before the temperature of the entire evaporator 34 is sufficiently raised. It may be supplied to the container 36.

The shift section 38 may be provided with a bypass passage for guiding the gas that has passed through a part of the catalyst included in the shift section 38 to the CO selective oxidation section 39 without passing through the rest of the catalyst.

FIG. 6 shows a state in which a bypass passage connecting the evaporator 34 and the reformer 36, the reformer 36 and the shift portion 38, and the shift portion 38 and the CO selective oxidation portion 39 is provided. . If at least one of these bypass flow paths is provided and the above-described control is performed, the effect of shortening the warm-up time of the downstream reactor can be obtained.

In particular, in a reactor such as the reformer 36 that performs an oxidation reaction, the effect of providing the above-described bypass passage can be remarkably obtained. In such a reactor, when the temperature of the catalyst rises above a predetermined temperature, heat is actively generated inside the reactor, so that the temperature of the downstream side of the reactor through which gas does not pass also rises more quickly.

D3. Modification 3 of the first embodiment: Further, the bypass flow passage does not necessarily have to be provided between the adjacent reactors. A bypass flow path may be provided so that the gas that has passed through a part of the predetermined reactor is supplied to the reactor disposed downstream of the reactor adjacent to this reactor. An example is shown in FIG. FIG. 7 shows a state in which the space between the first reaction section 21 and the second reaction section 22 and the flow path 76 are connected to each other in the fuel cell system 10 shown in FIG. 1 to provide the bypass flow path 277. Is shown. Bypass channel 2
77 includes a valve 225 driven by the control unit 60.
Is provided. By opening the valve 225, a part of the gas that has passed through the first reaction section 21 is guided to the CO selective oxidation section 39 without passing through the second reaction section 22 and the shift section 38.

With such a configuration, the second reaction section 22
And regardless of the warm-up state of the shift section 38, the high temperature gas is supplied from the first reaction section 21 to the CO selective oxidation section 39 via the bypass flow path 277 to warm up the CO selective oxidation section 39. Can be promoted. It should be noted that the high temperature gas that has passed through the first reaction section 21 is supplied to both the shift section 38 and the CO selective oxidation section 39 by using both the bypass channel 77 and the bypass channel 277 shown in FIG. Also good.

D4. Modification 4 of the first embodiment: In the above-described embodiment, the bypass passage is used from the time of start-up until the temperature of the reactor on the downstream side rises to a predetermined temperature. The bypass flow path may not be used until the temperature of the upstream part of the reactor is raised.

In such a case, in the fuel cell system 10 of the first embodiment shown in FIG. 1, the first reaction section 21
A temperature sensor for detecting the temperature may be further provided. FIG. 8 is a flowchart showing a reformed gas flow path control processing routine executed when performing control without using the bypass flow path 77 until the temperature of the first reaction section 21 is sufficiently raised.

This routine is executed when the fuel cell system 10 is started. When this routine is started, the control unit 60 outputs a drive signal to the valves 24 and 25 to open the valve 24 and close the valve 25 (step S200). When the fuel cell system 10 is started, gasoline is supplied to the heating unit 50 to start a combustion reaction in the heating unit 50, and gasoline and water are supplied to the evaporator 34 to be vaporized / heated and mixed. The gas is supplied to the reformer 36.
By controlling the open / closed state of each valve in step S200 as described above, when the fuel cell system 10 is started, the gas that has passed through the first reaction section 21 of the reformer 36 passes through the bypass flow passage 77. Instead, it passes through the second reaction section 22 and is supplied to the shift section 38.

Next, the temperature T ₂ of the first reaction section 21 is input by inputting the detection signal of the temperature sensor provided in the first reaction section 21 (step S210). Next, this catalyst temperature T ₂ and a predetermined reference temperature T set in advance
_B is compared (step S220). When the high temperature mixed gas is supplied from the evaporator 34, the inside of the reformer 36 becomes
The mixed gas gradually warms the first reaction section 21 from the upstream side. In step S220, the progress of warming up in the first reaction unit 21 is determined. In the first reaction section 21, the reference temperature T _B is
The catalyst temperature is set in advance as the catalyst temperature at which the shift reaction can proceed with sufficient activity.

In step S220, the catalyst temperature T ₂
When it is determined that is equal to or lower than the reference temperature T _B , the process returns to step S210 and the catalyst temperature T ₂ is input again. Thus, in step S220 until the catalyst temperature T ₂ is determined to have exceeded the reference temperature T _B, is repeated and loading of the catalyst temperature T _2, the operation of the comparison between the reference temperature T _B.

In step S220, the catalyst temperature T ₂
When it is determined that the temperature exceeds the reference temperature T _B , the valves 24, 2
A drive signal is output to 5 to close the valve 24 and open the valve 25 (step S100).
The steps after step S100 in FIG. 8 are the same as steps 100 to S130 shown in FIG. In this way, the gas that has passed through the first reaction section 21 is controlled to be supplied to the shift section 38 via the bypass passage 77 until the warm-up state of the shift section 38 reaches a predetermined state.

In this way, the gas valve 2 immediately after startup
Regardless of the open / closed state of 4, 25, the high temperature gas may be supplied to the downstream reactor via the bypass passage before the temperature of the entire upstream reactor is raised. As a result, the effect of shortening the warm-up time can be obtained.

D5. Modification 5 of First Embodiment: In the above-described embodiments, the bypass flow passage 77 is not used after the temperature of the second reaction section 22 is raised to some extent. The bypass flow path may be used until the entire battery system 10 is warmed up. In such a case, until it is determined that the warm-up of the fuel cell system 10 is completed, the second reaction unit 22 is heated by heat transfer even after the temperature detected by the temperature sensor 23 exceeds a predetermined temperature. The machine progresses. Further, the high temperature gas that has passed only the first reaction section 21 is continuously supplied to the shift section 38.

Until the warm-up of the fuel cell system 10 is completed, the gas passing through the first reaction section 21 is bypassed by the bypass passage 77.
FIG. 4 (B) shows how the catalyst temperature changes when the control that leads to FIG. When such control is performed, the catalyst temperature of the shift unit 38 is gradually increased and the shift unit 3
The temperature range where the catalyst temperature of 8 shows a sufficiently high activity (in the figure,
It stabilizes when it reaches a predetermined temperature within the temperature range indicated by the arrow.

D6. Modification 6 of the first embodiment: Further, the amount of gas bypassed to the downstream side does not have to be the total amount of the gas supplied to the reactor on the upstream side, and at least a part thereof may be passed. . For example, the first shown in FIG.
In the fuel cell system 10 of the embodiment, the opening degrees of the valves 24 and 25 are adjusted so that a part of the gas supplied to the first reaction section 21 passes through the second reaction section 22.
The rest may be passed through the bypass flow passage 77.
By bypassing at least a part of the gas before the temperature of the entire reactor on the upstream side is sufficiently raised, the effect of shortening the warm-up time can be obtained.

D7. Variant 7 of the first embodiment: Further, the amount of gas bypassed from the upstream reactor may not be constant, but may be changed as the warm-up progresses. For example, in the fuel cell system 10 of the first embodiment shown in FIG. 2, the openings of the valves 24 and 25 may be increased or decreased according to the progress of warming up. As the warming-up of the second reaction section 22 progresses, the bypass passage 77
It is also possible to perform control to increase the amount of gas passing through or to decrease it.

D8. Modified Example 8 of First Embodiment: In the above-described embodiment, the bypass passage is provided between the different types of reactors, but the same applies in a predetermined reactor in which the inside is divided into a plurality of reaction parts. It is also possible to provide a bypass path of. FIG. 9 is an explanatory diagram showing the configuration of a reformer 236 as a modified example of the first embodiment. This reformer 236
Is provided in place of the reformer 36 in a system similar to the fuel cell system 10 shown in FIG. In the following description, the same parts as those of the fuel cell system 10 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The reformer 236 includes a first reaction section 221 and a second reaction section 221.
The reaction section 222 and the third reaction section 223 are provided. The first reaction section 221 to the third reaction section 223 are provided with a honeycomb carrying a reforming catalyst, similarly to the first reaction section 21 and the second reaction section 22 in the reformer 36. The mixed gas supplied from the fuel gas flow path 74 to the reformer 236 is the first reaction part 22.
After passing through the first reaction section 222, the second reaction section 222, and the third reaction section 223 in this order, the reforming reaction is performed.

In addition, the first reaction section 221 and the second reaction section 22
2 and the second reaction section 222 and the third reaction section 22.
A bypass flow path 277 is provided to connect the space between the bypass flow path 277 and the space. The control unit 60 is provided in the bypass flow path 277.
A valve 225 driven by is provided. By opening the valve 225, a part of the gas that has passed through the first reaction section 221 is guided to the third reaction section 223 without passing through the second reaction section 222.

In such a reformer 236, when the valve 225 is controlled so that a part of the gas that has passed through the first reaction section 221 passes through the bypass flow passage 277 when warming up, the reformer 236. The effect of shortening the warm-up time can be obtained. That is, if the high-temperature gas that has passed through the first reaction section 221 is directly guided to the third reaction section 223, the temperature of the third reaction section 223 can be raised more quickly, and as a result, the reformer 236 as a whole can be heated. Warm-up time can be shortened.
At this time, the second reaction part 222 is
The temperature is raised by the gas supplied from the first reaction section 221 and is also raised by the heat transfer from the first reaction section 221 which has been previously raised.

E. Second Embodiment: FIG. 10 is an explanatory diagram schematically showing the configuration of a reformer 336 of the second embodiment. The reformer 336 is the same as the reformer 3 in the fuel cell system similar to the fuel cell system 10 of the first embodiment shown in FIG.
6 is provided instead. In the following description, the same parts as those of the fuel cell system 10 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The reformer 336 includes a first reaction section 321 and a second reaction section 321.
The reaction section 222 and the third reaction section 323 are provided. The first reaction section 321 to the third reaction section 323 are each provided with a honeycomb carrying a reforming catalyst, like the first reaction section 21 and the second reaction section 22 in the reformer 36. The mixed gas supplied from the fuel gas flow path 74 to the reformer 336 is the first reaction section 32.
It passes through the first reaction section 322, the third reaction section 322, and the third reaction section 323 in this order, and is used for the reforming reaction. Further, in the first reaction section 321 to the third reaction section 323, temperature sensors 86 to 88 for detecting the catalyst temperature as the internal temperature of each reaction section are provided in each reaction section. The detection signals of the temperature sensors 86 to 88 are input to the control unit 60.

Further, the reformer 336 includes the first reaction section 321.
-The 3rd reaction part 323 and the storage case 8 which stores these
A bypass portion 85, which is a space through which gas can flow, is provided between the bypass portion 85 and the gas. The bypass section 85 is provided with valves 81, 82, 83 driven by the control section 60. By adjusting the opening degree of the valve 81, the entire amount of the mixed gas supplied from the fuel gas flow path 74 is made to be supplied to the first reaction section 321, or a part of the mixed gas is supplied to the bypass section 85. It can be put in a leading state. By adjusting the opening degree of the valve 82, of the mixed gas flowing from the upstream side in the bypass section 85, the amount of gas introduced into the second reaction section 322 and the gas introduced into the bypass section 85 further downstream. The quantity and can be adjusted. Valve 8
By adjusting the opening of No. 3, the mixed gas flowing from the upstream side in the bypass section 85 can be introduced into the third reaction section 323.

FIG. 11 is a flow chart showing a mixed gas flow path control processing routine executed by the control unit 60 when the fuel cell system including the reformer 336 is started up. This routine is executed when the fuel cell system is started. When this routine is started, the control unit 60 causes the valve 8
The drive signal is output to 1 so that the entire amount of the mixed gas supplied to the reformer 336 is supplied to the first reaction unit 321 (step S300). As a result, the high-temperature mixed gas is supplied from the evaporator 34 via the fuel gas flow path 74, so that the temperature in the first reaction section 321 gradually rises from the upstream side and the temperature of the catalyst rises and the reforming occurs. The reaction gradually proceeds. As the temperature of the catalyst rises and the oxidation reaction is performed, the warm-up of the first reaction section 321 further progresses. At this time, the second reaction section 322 and the third reaction section 32
In No. 3, the gas whose temperature has been lowered by exchanging heat with the first reaction section 321 is supplied, so that the catalyst temperature starts to rise more gradually.

Next, by inputting the detection signal of the temperature sensor 86, the catalyst temperature T ₃ of the first reaction section 321 is input (step S310). Then, this catalyst temperature T
₃ is compared with a predetermined reference temperature T _C set in advance (step S320). Here, the predetermined reference temperature T
_C is preset as a catalyst temperature that allows the reforming reaction to proceed with sufficient activity in the first reaction section 321 when a gas mixture having a sufficiently high temperature is supplied from the evaporator 34. It is the temperature that I set.

In step S320, the catalyst temperature T ₃
When it is determined that is equal to or lower than the reference temperature T _C , the process returns to step S310 and the catalyst temperature T ₃ is input again. Thus, in step S320 until the catalyst temperature T ₃ is determined to have exceeded the reference temperature T _C, is repeated and loading of the catalyst temperature T _3, the operation of the comparison between the reference temperature T _C.

In step S320, the catalyst temperature T ₃
When it is determined that the temperature exceeds the reference temperature T _C , the valves 81 and 82 are set so that a part of the mixed gas supplied to the reformer 336 is guided to the second reaction section 322 via the bypass section 85. It drives (step S330). by this,
A mixed gas that has not been subjected to the reforming reaction in the first reaction section 321 is supplied to the second reaction section 322, and an oxidation reaction is performed in the second reaction section 322 using this mixed gas. Will be Due to the heat generated by such a reaction, warm-up of the second reaction section 322 proceeds. At this time, in the first reaction section 321, the remaining mixed gas is supplied so that the oxidation reaction continues to proceed and the catalyst temperature further rises. As a result, the temperature of the gas supplied from the first reaction section 321 to the second reaction section 322 also rises, so the second reaction section 322 is also heated by this gas.

Next, by inputting the detection signal of the temperature sensor 87, the catalyst temperature T ₄ of the second reaction section 322 is input (step S340). Then, this catalyst temperature T
₄ is compared with a predetermined reference temperature T _D set in advance (step S350). Here, the predetermined reference temperature T
_D is a temperature set in advance as a catalyst temperature that allows the reforming reaction to proceed with sufficient activity in the second reaction section 322.

In step S250, the catalyst temperature T ₄
When it is determined that is equal to or lower than the reference temperature T _D , the process returns to step S340 and the catalyst temperature T ₄ is input again. Thus, in step S340 until the catalyst temperature T ₄ is determined to have exceeded the reference temperature T _D, is repeated and loading of the catalyst temperature T _4, the operation of the comparison between the reference temperature T _D.

In step S350, the catalyst temperature T ₄
When it is determined that the temperature exceeds the reference temperature T _D , a part of the mixed gas supplied to the reformer 336 is introduced to the third reaction section 323 in addition to the second reaction section 322 via the bypass section 85. As described above, the valves 81, 82 and 83 are driven (step S360). As a result, the third reaction section 323 has
The mixed gas that has not been used for the reforming reaction is supplied to the first reaction section 321 and the second reaction section 322, and the oxidation reaction is performed in the third reaction section 323 using this mixed gas. become. The heat generated by such a reaction further warms up the third reaction section 323.

Next, it is determined whether or not the warm-up operation of the reformer 336 is completed (step S370). The completion of the warm-up operation of the reformer 336 is determined by, for example, the catalyst temperature of the third reaction section 323 detected by the temperature sensor 88 becoming a temperature at which the reaction proceeds without any problem under the condition of performing the steady operation. be able to. When it is determined in step S370 that the warm-up operation of the reformer 336 has ended, the reformer 3
The valve 81 is driven so that the total amount of the mixed gas supplied to 36 is guided to the first reaction section 321 (step S38).
0), this routine ends.

According to the reformer 336 of the second embodiment configured as described above, the unreacted mixed gas that has not been subjected to the reforming reaction is caused to flow to the downstream side by passing through the bypass section 85. It is supplied to the arranged second reaction section 322 and third reaction section 323. As a result, during the warm-up operation of the reformer 336, the oxidation reaction can proceed even in the second reaction section 322 and the third reaction section 323, and the second reaction section 322 and the third reaction section 323 are warmed up. And reformer 3
The warm-up time of the entire 36 can be shortened.

On the other hand, when the control using the bypass section 85 is not performed, the second reaction section 3 is not operated during the warm-up operation.
The oxidation reaction cannot proceed in 22 or the third reaction section 323. This is because, during the normal warm-up operation, as described above, the reformer is supplied with a much smaller amount of the reformed fuel than the reformable fuel that can be processed. Therefore, when the catalyst temperature of the first reaction section 321 rises to some extent, the total amount of the mixed gas supplied to the reformer 336 becomes the first amount.
When guided to the reaction section 321, most of the reformed fuel in the mixed gas is consumed by the reforming reaction in the first reaction section 321. Therefore, the warm-up of the second reaction section 322 and the third reaction section 323 depends on the heat of the gas supplied from the first reaction section 321 and the heat transfer, which requires a long time. By performing the above control using the bypass section 85, the second reaction section 322 and the third reaction section 322
The reaction section 323 can also cause an exothermic reaction to accelerate the warm-up of the entire reformer 336.

When performing the above control, for example,
The amount of the mixed gas supplied to the first reaction section 321 may be secured so that the oxidation reaction continues to proceed in the first reaction section 321 to the extent that the temperature of the first reaction section 321 can be maintained sufficiently high. Then, if the excess mixed gas is supplied to the downstream reaction section via the bypass section 85, the exothermic reaction is performed in the downstream section while the warm-up is proceeding from the upstream side, and the warm-up is efficiently performed. be able to.

In the second embodiment, the bypass section 85 is
It was formed as a space covering the first reaction part 321 to the third reaction part 323. By providing such a space,
It is possible to suppress heat dissipation from each reaction part. Therefore, by providing the bypass portion 85, it is possible to obtain the effect that the thermal efficiency in the reformer 336 can be improved during steady operation.

F. Modification of Second Embodiment: Furthermore, the following modifications can be made to the above embodiment.

D1. Modified Example 1 of Second Embodiment In the second embodiment, a bypass section 85 is provided in order to supply the mixed gas to the second reaction section 322 and the third reaction section 323 without passing through the first reaction section 321. However, different configurations are possible. For example, the bypass channels 77 and 1 described above
Like 77, a bypass flow path may be provided outside the storage case that stores the first to third reaction units, which connects the inlet of the reformer 336 and the reaction unit disposed on the downstream side. good.

D2. Modification 2 of the second embodiment: In step S320 and step S350 shown in FIG. 11, the reference temperature used when determining the warm-up state of each reaction part is sufficient to allow the reforming reaction to proceed. Although the catalyst temperature is used, this temperature may be set lower than the catalyst temperature during steady operation. For example, in the reformer 336 that uses gasoline as the reforming fuel, the temperature of the catalyst included in each reaction unit is controlled to be 600 ° C. or higher during steady operation. However, even if the catalyst temperature is lower than 600 ° C., the oxidation reaction can proceed with some activity. Therefore, the reference temperature may be set to a temperature lower than 600 ° C.

During the warm-up operation of the reformer 336, if there is a part where the temperature is low in the reformer 336,
Since the gas passing through the reformer 336 contains a predetermined amount of water vapor, water may condense in a place where the temperature is low. When the water is condensed, the condensed water covers the surface of the catalyst to hinder the reaction, or heat is required to vaporize the condensed water, which causes the completion of warming up to be delayed. Therefore, the above 6
Even if the temperature is lower than 00 ° C., condensed water is generated in the entire reformer 336 by setting the above-mentioned reference temperature so that the oxidation reaction is sufficiently higher than 100 ° C. and can proceed with a certain degree of activity. Can be prevented.

D3. Modification 3 of the second embodiment: valves 81, 8
Various modifications can be made to the control of the open / closed states of Nos. 2,83. For example, in FIG. 11, step S35
Even after the catalyst temperature T ₄ exceeds the reference temperature T _D at 0,
It was decided to continue supplying the mixed gas to the second reaction section 322 via the bypass section 85. On the other hand, the catalyst temperature T ₄
After the temperature exceeds the reference temperature T _D , the mixed gas is not supplied to the second reaction section 322, and the first reaction section 321 and the third reaction section 32 are not supplied.
The mixed gas may be supplied only to 3. In such a case, in the subsequent steps, the second reaction section 322 is warmed up by the heat and heat transfer of the gas supplied from the first reaction section 321.

Further, in FIG. 11, when it is determined in step S370 that the warm-up operation of the reformer 336 has been completed, the introduction of the mixed gas to the bypass section 85 is stopped, but the warm-up of the entire fuel cell system is stopped. The bypass unit 85 may be used during operation. That is, the mixed gas may be supplied to the reaction section on the downstream side by using the bypass section 85 until the steady operation is started.

D4. Modification 4 of Second Embodiment: In the second embodiment, the warm-up of the reformer having a plurality of reaction parts (first reaction part 321 to third reaction part 323) has been described.
Such a warm-up method can be applied to other types of reactors such as an evaporator, a shift section, and a CO selective oxidation section. Similar to the reformer 336 shown in FIG. 10, if a plurality of reaction parts connected in series and a bypass flow path for guiding gas to the downstream side without passing through the reaction part on the upstream side are provided, the same effect can be obtained. It can be controlled. Before the temperature of the reaction section on the downstream side rises sufficiently, unreacted gas is supplied through the bypass flow path to allow the exothermic reaction to proceed in the reaction section on the downstream side, thereby increasing the warm-up time of the entire reactor It can be shortened. A reactor in which an oxidation reaction proceeds, such as a reformer or a CO selective oxidation unit, uses heat generated by an exothermic reaction to accelerate warming, as compared with a reactor in which an equilibrium reaction proceeds, such as a shift unit. Greater effect can be obtained.

G. Other Modifications: The present invention is not limited to the above-described embodiments and embodiments, and can be implemented in various modes without departing from the scope of the invention. For example, the following modifications are also possible. It is possible.

G1. Modification 1: First and second described above
In the examples, in each reactor, or in the reaction part formed by dividing the inside of a predetermined reactor into a plurality of parts, the progress state of the warm-up was judged by detecting the temperature, but it was judged by different methods. Is also good. For example, in the fuel cell system 10 of the first embodiment shown in FIG. 2, a carbon monoxide concentration sensor may be provided in the flow path 76 in order to determine the warm-up state of the shift section 38. Shift unit 38
When the temperature of the catalyst included in the shift temperature rises and the shift reaction proceeds with sufficient activity, the concentration of carbon monoxide in the gas discharged from the shift unit 38 decreases. Therefore, by detecting the concentration of carbon monoxide, It is possible to judge the warm-up state. Similarly, in order to determine the warm-up state of the reformer or the reaction section of the reformer, the hydrogen concentration in the gas discharged from the reformer or the reaction section of the reformer is detected. A sensor may be provided.

The progress of warm-up can also be determined by a method other than measuring a value that directly reflects the state of the catalyst, such as temperature or a predetermined component in gas. For example, when the environment for operating the fuel cell system is within a certain temperature range, the progress of warming up may be determined based on the elapsed time after the fuel cell system is started.

G2. Modification 2: In addition, when the warm-up operation is performed at the time of starting the fuel cell system, a reaction different from that in the steady operation may be performed in the reactor. For example, in the reformer of the above-described embodiment, the steam reforming reaction and the partial oxidation reaction proceed during the steady operation, but during warming up, the ratio of the partial oxidation reaction is increased, or Instead of the partial oxidation reaction, a complete oxidation reaction may be allowed to proceed. Such a reaction can be performed by increasing the ratio of the amount of air supplied to the reformer by the blower 53 shown in FIG. As a result, in the reformer, the oxidation reaction can proceed more actively, the amount of heat generated in the reformer can be increased, and the warm-up can be promoted.

G3. Modification 3: In the above-described embodiments, each reactor (reaction part) is provided with a honeycomb carrying a catalyst, but may have a different configuration. For example, each catalyst may be supported on pellets, or the catalyst may be molded into pellets, and each reactor (reaction part) may be filled with such pellets. In such cases,
In the reactor filled with pellets (reaction part), a part upstream of the outlet from which gas is discharged during steady operation,
A bypass flow path that connects the reactor (reaction part) disposed on the downstream side of the reactor (reaction part) is provided.

G4. Modification 4: The fuel cell system can be further modified in various ways. Examples of the reforming fuel include liquid hydrocarbons such as gasoline described above, gaseous hydrocarbons such as natural gas, alcohols such as methanol and aldehydes, and various hydrocarbon-based hydrocarbons capable of generating hydrogen by a reforming reaction. Fuel can be selected. Depending on the reforming fuel used, the type and reforming temperature of the reforming catalyst, or the catalyst temperature serving as a reference when performing control to bypass the gas may be set appropriately. Further, as the fuel cell included in the fuel cell system to which the present invention is applied,
Other than the polymer electrolyte fuel cell, any material may be used as long as it performs the electrochemical reaction using the reformed gas.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a fuel cell system 10.

FIG. 2 is an explanatory diagram showing in more detail the state of connection between a reformer and a shift unit.

FIG. 3 is a flowchart showing a reformed gas flow path control processing routine executed when the fuel cell system 10 is started up.

FIG. 4 is an explanatory diagram showing how the temperature of the shift catalyst rises during warm-up operation.

FIG. 5 is an explanatory diagram showing states of a reformer 136 and bypass passages 177 and 178 connected to the reformer 136 as a modified example of the first embodiment.

FIG. 6 is an explanatory view showing a state in which a bypass passage is provided between adjacent reactors.

FIG. 7 is an explanatory diagram showing a state in which a space between the first reaction section 21 and the second reaction section 22 is connected to a flow path 76 to provide a bypass flow path 277.

FIG. 8 is a flowchart showing a reformed gas flow path control processing routine.

FIG. 9 is an explanatory diagram showing a configuration of a reformer 236 as a modified example of the first embodiment.

FIG. 10 is an explanatory diagram showing a configuration of a reformer 336 according to a second embodiment.

FIG. 11 is a flowchart showing a mixed gas flow path control processing routine.

[Explanation of symbols]

10 ... Fuel cell system 21 ... First reaction part 22 ... Second reaction part 23 ... Temperature sensor 24, 25, 125, 126, 225 ... Valve 30 ... Reforming fuel tank 32 ... Water tank 34 ... Evaporator 36, 136, 236, 336 ... Reformer 38 ... shift part 39 ... CO selective oxidation unit 40 ... Fuel cell 42 ... Blower 43 ... Oxidizing gas flow path 50 ... Heating section 52, 53, 54 ... Blower 56, 57, 58 ... Pump 60 ... Control unit 62 ... I / O port 64 ... CPU 66 ... ROM 68 ... RAM 70 ... Fuel flow path 71 ... Fork road 72 ... Water flow path 73 ... Fuel flow path 74 ... Fuel gas flow path 75 ... Gas flow path 76 ... Channel 77, 177, 277 ... Bypass channel 78 ... Fuel gas flow path 79 ... Anode exhaust gas passage 81, 82, 83 ... Valve 85 ... Bypass section 86-88 ... Temperature sensor 89 ... Storage case 121, 221, 321 ... First reaction part 122, 222, 322 ... Second reaction section 123, 223, 333 ... Third reaction section 178 ... Bypass channel

Claims (9)

[Claims] 1. A fuel reformer for reforming a hydrocarbon fuel to produce a hydrogen-rich gas, comprising a catalyst for promoting a reaction relating to the production of the hydrogen-rich gas, and a first gas inlet port. A first reaction part having a first gas outlet and a bypass gas outlet provided between the first gas inlet and the first gas outlet, and the production of the hydrogen-rich gas A second reaction part including a second gas inflow port to which the gas is supplied via the first reaction part, and a second gas outflow port, the second reaction part being provided with a catalyst for promoting the reaction relating to By a bypass flow path connecting the bypass gas outlet and the second gas inlet, a warm-up state determination unit that determines a warm-up state in the second reaction unit, and a warm-up state determination unit It is judged that the warm-up state has reached a predetermined state. Until then, at least a part of the gas introduced into the first reaction part is supplied to the second reaction part through the bypass flow path so that the gas flow path is switched. A fuel reformer comprising a switching unit. 2. The fuel reformer according to claim 1, wherein the first reaction section is a reforming section including a reforming catalyst that promotes a reforming reaction. 3. The fuel reformer according to claim 1, wherein the first reaction section includes a shift catalyst that promotes a shift reaction that produces hydrogen and carbon dioxide from carbon monoxide and water vapor. Is a fuel reformer. 4. A fuel reformer for reforming a hydrocarbon-based fuel to produce a hydrogen-rich gas, comprising a plurality of reaction parts connected in series so that the gas sequentially passes from the upstream side, A reactor containing a catalyst that promotes a reaction involving the generation of the hydrogen-rich gas that is accompanied by heat generation, and a part of the gas supplied to the reactor, A bypass flow path leading to a downstream reaction section other than the most upstream reaction section without passing through the most upstream reaction section, and a warming in the downstream reaction section. A warm-up state determination unit that determines a machine state, and until the warm-up state determination unit determines that the warm-up state has reached a predetermined state, part of the gas supplied to the reactor is , The reaction on the downstream side through the bypass channel As it supplied to the fuel reformer and a passage switching unit for switching the flow path of the gas. 5. The fuel cell reforming apparatus according to claim 4, wherein the reactor is a reforming section including a reforming catalyst that promotes a reforming reaction. 6. The fuel reformer according to claim 4, wherein the reactor includes a catalyst that promotes a carbon monoxide selective oxidation reaction that oxidizes carbon monoxide in preference to hydrogen in a hydrogen-rich gas. A fuel reformer that is a carbon selective oxidation unit. 7. A fuel cell system, which receives a supply of a fuel gas to obtain an electromotive force by an electrochemical reaction, comprising the fuel reforming device according to claim 1, wherein the fuel reforming device is generated. A fuel cell system using a hydrogen-rich gas as the fuel gas. 8. A method for warming up a fuel reforming apparatus for reforming a hydrocarbon-based fuel to generate a hydrogen-rich gas, comprising: (a)
A catalyst that accelerates the reaction relating to the generation of the hydrogen-rich gas is provided, and a first gas inlet, a first gas outlet, and the first gas inlet and the first gas outlet are provided. A step of preparing a first reaction part having a bypass gas outlet provided, and (b) a catalyst for accelerating a reaction relating to the production of the hydrogen-rich gas, and the step of passing through the first reaction part. Preparing a second reaction part having a second gas inlet to which gas is supplied and a second gas outlet, (c) the bypass gas outlet and the second gas inlet A step of preparing a bypass flow path for connecting to each other; (d) a step of determining a warm-up state of the second reaction section in the second reaction section; and (e) a step of (d) Until it is determined that the warm-up state has reached a predetermined state, Through the bypass passage, the warm-up method of a fuel reforming apparatus and a feeding at least a portion of the gas introduced into the first reaction portion in the second reaction portion. 9. A method for warming up a fuel reformer for reforming a hydrocarbon-based fuel to produce a hydrogen-rich gas, comprising: (a)
A plurality of reaction parts connected in series so that the gas sequentially passes from the upstream side is provided, and a catalyst that promotes a reaction that is associated with the production of the hydrogen-rich gas and is accompanied by heat generation is accommodated in each of the reaction parts. Preparing a reactor for
(B) Except for the reaction section arranged at the most upstream side, without passing a part of the gas supplied to the reactor through the reaction section arranged at the most upstream side of the plurality of reaction sections. A step of preparing a bypass flow path leading to the reaction section on the downstream side of
(C) the step of determining the warm-up state in the reaction section on the downstream side, and (d) the step of (c), the reaction until the warm-up state reaches a predetermined state. And a step of supplying a part of the gas supplied to the reactor to the downstream reaction section via the bypass flow path.